# Defintion of derivative

• Apr 3rd 2008, 07:32 PM
indigosheen
Defintion of derivative
How do you get the derivative of 2(x)^(1/2) using the definition of derivative?
• Apr 3rd 2008, 07:34 PM
Mathstud28
you
you use the quotient differnece if you know what that is?
• Apr 3rd 2008, 07:38 PM
indigosheen
Yeah, but I always seem to get confused on how to fit f(x) into
f '(x)=f(x+h)-f(x)/h
• Apr 3rd 2008, 07:41 PM
Mathstud28
in this
first off remeber it is the lim as x goes to o and in this case f(x+h)= $2(x+h)^{\frac{1}{2}}$ and f(x)= $2(x)^{\frac{1}{2}}$...so it would be $\frac{2(x+h)^{\frac{1}{2}}-2(x)^{\frac{1}{2}}}{h}$ the limit of that as h goes to 0